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| United States Patent |
6,218,940
|
|
Rejc
, et al.
|
April 17, 2001
|
Safety device for motor-operated doors
Abstract
A safety device for preferably vertically moving, motor-driven doors such
as, for example, segmented doors or rolling shutter doors whose door leaf
is capable of being moved in a guided fashion is described. The movement
path of a leading door edge is monitored by a preferably optical beam
protection, preferably on the basis of infrared beams. The beam protection
has at least two, preferably at least three or a plurality of preferably
parallel beams which are arranged staggered in the direction of movement
of the door and which are emitted on one side of the door and received or
reflected on the other side of the door. Furthermore, a safety circuit is
provided with which the closing movement of the door is stopped if an
obstacle is sensed in the movement path of the door. The beam protection
is arranged in such a way that the beam area defined by the beams has at
least one line in common with the movement area through which the leading
door edge passes, and that the autonomously operating safety device has a
beam-state control device which assigns different activation states to the
beams as a function of the position and of the movement of the door.
| Inventors:
|
Rejc; Gabrijel (Landshut, DE);
Eichstetter; Karl (Tiefenbach, DE)
|
| Assignee:
|
Efaflex Tor und Sicherheitssysteme GmbH & Co, (DE)
|
| Appl. No.:
|
148311 |
| Filed:
|
September 4, 1998 |
Foreign Application Priority Data
| Sep 09, 1997[DE] | 197 39 543 |
| Current U.S. Class: |
340/556; 250/221 |
| Intern'l Class: |
G08B 013/18 |
| Field of Search: |
340/555,556,557,545.3,686.6
250/221
318/280,466,256,264
|
References Cited
U.S. Patent Documents
| 4166369 | Sep., 1979 | Nakajima.
| |
| 4750592 | Jun., 1988 | Watt.
| |
| 4794248 | Dec., 1988 | Gray.
| |
| 4818866 | Apr., 1989 | Weber | 250/221.
|
| 4853531 | Aug., 1989 | Rejc.
| |
| 4953608 | Sep., 1990 | Larsson | 160/1.
|
| 5233185 | Aug., 1993 | Whitaker.
| |
| 5286967 | Feb., 1994 | Bates | 250/221.
|
| 5601134 | Feb., 1997 | Pinkalla.
| |
| 5602526 | Feb., 1997 | Read.
| |
| 5894267 | Apr., 1999 | Blair.
| |
| 5969637 | Oct., 1999 | Doppelt et al. | 340/825.
|
| Foreign Patent Documents |
| 3603940 A1 | Feb., 1986 | DE.
| |
| 86 03 304 | Aug., 1986 | DE.
| |
| 3790010 | Jan., 1987 | DE.
| |
| 3709592 A1 | Mar., 1987 | DE.
| |
| 36 18 766 A1 | Dec., 1987 | DE.
| |
| 4205251 A1 | Feb., 1992 | DE.
| |
| 43 34 785 A1 | May., 1994 | DE.
| |
| 4424537 A1 | Jul., 1994 | DE.
| |
| 29707448 U1 | Apr., 1997 | DE.
| |
| 19601660 A1 | Jul., 1997 | DE.
| |
| 19604900 A1 | Aug., 1997 | DE.
| |
| 0284066 | Sep., 1988 | EP.
| |
| 0 676 524 A1 | Mar., 1994 | EP.
| |
| 0 789 182 | Aug., 1997 | EP.
| |
| 2 685 496 | Jun., 1993 | FR.
| |
| 09 189 183 | Jan., 1996 | JP.
| |
Other References
Patent Abstract of Japan; Inventor: Masaji et al; Publication No. 09189183;
Jul. 1997.
U.S. application No. 09/148,312 of Rejc filed Sep. 4, 1998.
|
Primary Examiner: Mullen; Thomas
Attorney, Agent or Firm: Nixon & Vanderhye PC
Claims
What is claimed is:
1. A safety device for externally-operated moving doors having a door leaf
selectively moved in a guided fashion to close a door opening, said safety
device including:
an optical beam protection assembly for monitoring a movement path of a
leading edge of said door leaf, said optical beam protection assembly
including a plurality of beam emitters for emitting a plurality of beams
from one side of the door opening toward another side of the door opening
in a direction generally transverse to said movement path; and
a safety circuit for selectively at least one of stopping and reversing a
closing movement of the door leaf upon sensing an obstacle in the movement
path of the door leaf, wherein said beams of said protection assembly
define a beam area that has at least one line, oriented in a door movement
direction, in common with a movement area through which the leading door
edge passes and wherein the safety device has a beam state control device
that assigns one of a plurality of activation states to each of the beams
as a function of the position and the movement of the door leaf.
2. The safety device as claimed in claim 1, wherein the beam area is a
plane.
3. The safety device as claimed in claim 1, wherein the beam area coincides
with the movement area.
4. The safety device as claimed in claim 1, wherein the beam protection
assembly comprises a photoelectric area sensor.
5. The safety device as claimed in claim 1, wherein said beam state control
device also determining the position of the leading edge of the door leaf,
and wherein the beam-state control device assigns at least the beam which
is nearest to the leading edge and is not covered by the door leaf an
inactive transition state (ZERO) between an active state (1) and a passive
state (X).
6. The safety device as claimed in claim 5, wherein the beam state control
device includes a circuit which, as the door leaf crosses, during its
closing movement, a said beam which is in the transition state (ZERO),
changes a next beam in the direction of closing movement to the transition
state (ZERO).
7. The safety device as claimed in claim 5, wherein the number of beams set
to the transition state (ZERO) can be changed with the speed of movement
of the door.
8. The safety device as claimed in claim 5, wherein a circuit is provided
which, as the door leaf crosses, during its closing movement, a said beam
which is in the transition state (ZERO), sets to the transition state
(ZERO) a beam that is in the active state (1) and is nearest to the
leading edge of the door leaf.
9. The safety device as claimed in claim 5, wherein the beams of said
plurality of beam that assigned the passive state (X) are sequentially
switched into the active state (1) during opening of the door leaf.
10. The safety device as claimed in claim 1 wherein a distance of the beams
from one another decreases in the direction of the closing movement of the
door leaf.
11. The safety device as claimed in claim 1, wherein the leading door edge
of the door leaf moves vertically.
12. The safety device as claimed in claim 1 for monitoring a rolling
shutter door or folding door in which at least the leading section of the
door leaf is guided in lateral guide structures provided on each side of
the door opening, and wherein the components of the optical beam
protection assembly are arranged one of on and adjacent the guides.
13. The safety device as claimed in claim 12, wherein the beam protection
assembly is a photoelectric area sensor including photoelectric strips,
and wherein said photoelectric strips are integrated into the guide
structures.
14. A safety device for moving externally operated doors having a door leaf
selectively moved in a guided fashion to close a door opening, comprising:
an optical beam protection assembly for monitoring a movement path of a
leading door edge of said door leaf and which generates a plurality of
beams that are staggered along a direction of movement of the door leaf
and are each emitted from a side of the door opening toward an opposite
side of the door opening, and
a safety circuit with which the closing movement of the door leaf is
reversed or stopped upon sensing an obstacle in the movement path of the
door leaf,
wherein the beam protection assembly is disposed so that a beam area
defined by the beams has at least one line oriented to intersect a
movement area through which the leading door edge of the door leaf passes,
and
the safety device has a beam state control device for automatically
reducing a door opening area monitored by the beams of the optical beam
protection assembly as a function of the progressing obstruction of beams
by the door leaf.
15. An apparatus for controlling the movement of a system component along a
predetermined movement path, comprising:
a beam emitting assembly including a plurality of beam emitters that emit a
plurality of beams from transmitters to receivers, wherein the beams are
detected by the receivers for avoiding undesired collision of the moving
system component with a foreign object, the plurality of beams being
arranged to traverse a movement path of the system component to define a
scanning field; and
a safety circuit for selectively at least one of stopping and reversing a
movement of the system component upon sensing a foreign object in the
scanning field, and wherein the safety device has a beam state control
device that assigns one of a plurality of activation states to each of the
beams as a function of the position and the movement of the system
component, said beam state control device being adapted to automatically
assign a passive state (X) to those transmitters, receivers or pairs
thereof that the system component has already passed, a transition state
(ZERO) to the transmitter, receiver or pair thereof of which the
corresponding beam will be crossed next during the movement of the system
component, and an active state (1) to remaining transmitters, receivers or
pairs thereof in a part of the movement path of the system component into
or through which the system component has not yet passed.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a safety device for
motor-operated doors such as, for example, segmented doors or rolling
shutter doors. The safety device is used to sense an object located in the
movement path of a door, rolling grille, lift away shutter door and the
like.
1. Description of the Related Art
Such safety systems are known, for example, from the documents DE-U-8615042
or DE-A-3416546. According to DE-U-8615042, a safety strip, composed of a
tube made of elastomeric material, of a termination profile is provided on
one side with a lamp and on the other side with a light-sensitive
resistance element. If the safety strip strikes an obstacle, the light
beam is interrupted, causing a switching pulse which activates the engine
brake to be generated.
DE-A-3416546 relates to a safety device for stopping motor-driven objects.
In order to bring about improved response of the safety device for
stopping motor-driven objects having a photoelectric barrier arrangement,
the photoelectric barrier arrangement is composed of a light transmitter
and a light receiver which are arranged at the two ends of a profiled rail
having a light duct. When an obstacle is struck, the profiled rail
composed of an elastically deformable material is squeezed together,
causing the cross-section of the light duct to be reduced, so that the
light beam is interrupted.
However, in these elastically deformable safety strips, adequate protection
against injuries and damage is provided only if their deformation range
corresponds to the follow-on travel of the leading edge of the terminating
profile from the activation of the switching device up to the point where
it is braked to a complete standstill. Owing to the weight, and in
particular the kinetic energy, of the door leaf and of the terminating
profile, there is, apart from the switching deceleration, a relatively
long follow-on travel so that high, and thus expensive, safety strips have
to be used.
A further disadvantage of such safety strips comprising profiled
elastomeric material is, in addition to the unavoidable activation force
and the resistance force resulting from its deformation, the fact that
switching decelerations, or even switching failures, may occur depending
on the direction of impact.
Owing to these problems, the procedure of arranging photoelectric barrier
arrangements at a distance corresponding at least to the follow-on travel
of the door leaf, in front of the leading edge of the terminating profile
of the leaf door, so that the movement of the door leaf is stopped if an
obstacle interrupts the light beam of the photoelectric barrier
arrangement. Since the light beam runs at a distance in front of the
terminating profile of the door leaf, it is ensured that the terminating
profile does not come into contact with an obstacle which interrupts the
light beam.
Examples of this are given in the documents EP-B-0325602 and EP-B-0284066.
EP-B-0325602 discloses a safety device for rolling shutter doors in which
the switching device is composed of a photoelectric barrier whose
transmitter and pickup elements are arranged on each side of the
terminating profile underneath said profile on supporting arms, at a
distance corresponding to the braking distance. The supporting arms are
guided in a sliding fashion in respective securing elements which are
connected to a lower part of the door leaf. If the supporting arm strikes
against the ground or a stop, the transmitter and pickup elements are
displaced relative to the door leaf and toward it and arrive, at the end
of the closing movement of the door, at a position which lies at least at
the level of the lower terminating edge of the door leaf.
EP-B-0284066 discloses a high-speed door with a switching device which is
provided in the region of the lower edge of the terminating profile and
allows the brake to engage when said switching device is activated. The
switching device is composed of a photoelectric barrier whose transmitter
and sensor element are arranged on each side of the terminating profile at
a distance below it corresponding to the braking distance, in the region
of the lower ends of plungers which are guided so as to be capable of
insertion in guides on the terminating profile or lateral blade-like
projections. When the plungers strike the ground or a stop, the plungers
dip into the guides so that the terminating profile can be supported on
the ground.
In the two examples mentioned above, the transmitter and sensor element are
arranged on part of the door leaf, with the result that the transmitter
and sensor elements are moved with the door leaf. Owing to this movement,
the electrical leads and other components of the electric circuit which
extend between the door leaf and frame are subject to strong dynamic loads
which are caused by vibrations in the door leaf and continuous bending
stresses. In addition, dirt, dust and water may become deposited on
various electrical system components and lead to a decrease in the
performance or a malfunction of the system. In many cases, the fact that
the electrical supply of the sensor and transmitter element has to be led
through the door, so that the design of the door or of the door segments
has to be adapted to this, proves problematic in these known systems. This
adversely affects the flexibility of the user, but also of the
manufacturer, as far as the door design is concerned.
Photoelectric area sensor systems are also known for protecting doors, said
sensors being mounted either on one side of the door leaf or else, in
order to improve the protection, on both sides of the door leaf. In the
first case, adequate protection of persons and property is not provided on
the side of the door leaf which is not equipped with the area sensor. In
the latter case, the expenditure is too high and the photoelectric area
sensor system is too expensive. In addition, it is a common feature of
both systems that they are susceptible to incorrect switching if, for
example, power supply components such as, for example, coiled cables, dip
into the beam path of the photoelectric area sensor in an uncontrolled
fashion due to external weather influences or the door leaf itself bulges
out when subjected to the wind.
SUMMARY OF THE INVENTION
The object of the present invention is therefore to provide a safety device
of the generic type which, with simple mounting facility, provides a
maximum degree of system and personal safety for a door of any desired
design and requires only low expenditure on control equipment.
According to the invention, a safety device which operates autonomously is
provided, the beam-state control device of which operates in such a way
that, once the position of the door (initialization phase) has been
determined, a predetermined activation algorithm for the beam protection,
for example in the form of individual photoelectric barrier systems, can
run automatically. The algorithm according to the invention makes it
possible to position the beams in the door movement path, with the result
that a single photoelectric area sensor system is sufficient to monitor
the entire movement path of the door, as a result of which the expenditure
on technical equipment is further reduced. Because the actual position of
the door determines the various activation states of the photoelectric
barriers, the safety device is synchronized automatically with the
movement of the door. It is no longer necessary to connect the control
system of the door to be monitored, with the result that the safety device
according to the invention can be retrofitted as, as it were, a
"stand-alone solution" for any commercially available door or the like. In
addition, the control circuit which is necessary is simple. The safety
device according to the invention provides an unprecedented level of
monitoring safety. This is because any object which is in contact with the
monitored moving face of the door leaf inevitably causes the safety device
to respond and immediately prevents activation of the drive unit for the
door. Possible control errors, but also movement deviations owing to
inertia (running-on of relatively large moving masses) are thus
compensated from the outset.
Commercially available photoelectric barrier strips may be used in an
embodiment of the invention.
Maximum safety is achieved with the development of because both lateral
guides are thus also completely protected against unintentional
intervention in it. Here, the additional advantage is obtained that the
strip or strips of the photoelectric area sensor is covered by the means
of guiding the door and are thus simultaneously protected against damage.
A costly starting-up protection can thus be dispensed with.
Basically, to implement the solution principle according to the invention
it is sufficient to implement a single pair of beams. The sensitivity of
the safety device can be increased as desired and according to
requirements if the beam protection is performed, according to an
embodiment of the invention, by a photoelectric area sensor.
In a preferred embodiment, a device for determining the position of the
closing edge of the door is provided and the beam-state control device is
designed so that at least the beam which is nearest to the closing edge
and is not covered by the door is assigned an inactive transition state
(ZERO) between an active state (1) and a passive state (X). Further, a
circuit is preferably provided which, as the door crosses during its
closing movement the at least one beam which is in the transition state
(ZERO), changes the next beam in the direction of closing movement from
the active state (1) to the transition state (ZERO). This algorithm
enables the beams through which the closing edge of the door successively
passes to be placed sequentially and automatically into a passive state X,
an inactive state 0 and an active state 1. These states are passed through
sequentially with the movement of the leading edge.
Advantageously, the number of beams set to the transition state (ZERO) can
be changed with the speed of movement of the door. This makes it possible,
when required, to perform adaptation to the movement speed of the door in
order to allow for the mass inertia of the door.
Feature that the beam which is interrupted by the closing edge and is in
the transition state (ZERO) sets to the transition state (ZERO) the beam
which is nearest in the direction of the closing movement of the door and
is in the active state (1) leads to an advantageous signal flow in the
system and to a continuous maximum safety state of the beams, even if the
door is opened only slightly and then closed again.
If a buffering device is provided, the safety device may simultaneously be
used as a detector device for determining the position and the direction
of movement of the door.
In a preferred embodiment of the invention, the maximum area taken up by
the safety device is reduced to reasonable dimensions of, for example, 2.5
m. The expenditure on examining the position, and thus on the safety
device, is thus further reduced.
By providing a device wherein the distance of the beams from one another
decreases in the direction of the closing movement of the door and/or the
photoelectric area sensor is actuated at least in certain areas in such a
way that a transmitter beam is evaluated by at least two receivers, enable
the sensitivity of the safety device to be kept particularly high wherever
specific hazard scenarios occur, such as for example at a low height above
the ground, at which level flat extension arms of forklift trucks move.
The cross-beam technology has here the particular advantage that
relatively simple photoelectric protection strips with a relatively large
pitch pattern and identical pitch of the transmitter/receiver can be used.
The safety device is not restricted to any orientation of the door movement
or to specific door leaf designs.
If the strips of the protective photoelectric area sensor are arranged on
the guides, the area covered by the photoelectric area sensor approximates
so closely to the area of movement that sufficient safety is already
provided for a large part of the instances of use.
A maximum degree of safety is obtained wherein the photoelectric strips of
the beam protection are integrated into the guide profile, with the
particular advantage of the easy retrofitability into existing guide
systems.
Further features and advantages of the present invention are apparent from
the description below of preferred embodiments of the present invention
with reference to the appended drawing, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a partially sectional front view of a rolling shutter door for
which the safety device according to the invention is provided;
FIG. 2 shows the view according to "II" in FIG. 1;
FIG. 3 shows a view, similar to that in FIG. 2, of a variant;
FIG. 4 shows a side view according to "IV" in FIG. 1;
FIG. 5 shows a view, similar to FIG. 4, of a variant of the door;
FIG. 6 shows section "VI--VI" in FIG. 4;
FIG. 7 shows a section, corresponding to FIG. 6, of a variant of the guide
profile;
FIG. 8 and FIG. 9 show block circuit diagrams of the actuation and
evaluation device of the safety device; and
FIG. 10 shows a flowchart for explaining the mode of operation of the
safety device.
DETAILED DESCRIPTION OF THE INVENTION
In the description of the figures, those components which correspond to one
another are provided with similar reference symbols, in front of which
there is merely a different ordinal number.
A rolling shutter door 11 of the width BR and height HR is composed, in a
known manner essentially of two laterally arranged hollow guide profiles
12 and 13 with U-shaped cross sections, a cross member 14 which rests on
the lateral guide profiles and in which a motor and a winding shaft which
is driven by the motor are accommodated, and a flexible door leaf 15 which
is guided in vertically extending slit-like guides in the lateral guide
profiles 12 and 13 and is wound onto the winding shaft.
Since the rolling shutter door for which the safety device according to the
invention is used corresponds to a generally known rolling shutter door, a
more precise description of the rest of its design will not be given here.
A safety device which is independent of the door controller, i.e. operates
autonomously and is preferably optical, is assigned to the rolling shutter
door 11. For this purpose, on each side of the door leaf 15 there is a
strip 17, 18 of a photoelectric area sensor arrangement, for example on
the basis on infrared beams, one strip accommodating the photoelectric
transmitter and the other strip the photoelectric receiver so that a
plurality of one-way photoelectric barriers with the beams 19-1 to 19-n
are formed.
In the embodiment shown, each transmitter is assigned a receiver. In
addition, the beams run parallel to one another. However, this is not
absolutely necessary. A transmitter may be assigned a plurality of
receivers. In addition, the beams 19 may also run obliquely.
The strips 17, 18 are attached in such a way that the area 20 covered by
the light beams 19 has at least one line 123 (FIG. 3) in common with the
area 122 of movement (FIG. 3) which the leading door edge 21 of the door
leaf 15 passes through. In the embodiment according to FIGS. 1, 2, 4 and
5, the planes coincide, i.e. the photoelectric area sensor lies directly
in the closing plane of the door leaf.
All the embodiments have in common that the strips 17, 18, and 117, 118 are
attached to the guide rails 12, 13 and 112, 113. According to FIGS. 2, 4
and 5, they are arranged inside the guide rail and/or the guide profiles
12, 13; in the embodiment according to FIG. 3 they are attached to the
side of the profiles 112, 113, specifically to different sides of the door
leaf.
The photoelectric barrier arrangement is used to monitor the closing
movement of the door in order to exclude the possibility of the leading
edge of the door striking an obstacle. FIG. 5 shows that the height H to
be monitored may be appropriately limited to a reasonable dimension, for
example to 2500 mm. The figure also shows that the door leaf may be of any
desired shape, for example may be formed of folded segments 224. The
leading edge 221 is in turn guided in a guide profile 213 in which the
photoelectric strip 218 may also be accommodated.
FIGS. 6 and 7 show variants of the arrangement of the photoelectric strips
in or on the respective guide profile:
According to FIG. 6, the guide profile 312 is provided with a further
profiled chamber which is adapted to the photoelectric strip 317 and
adjoins the guide chamber 325 for a roller 326 of the door leaf 315. The
gate is retrofitted here with the safety device according to the invention
by exchanging the guide profile.
According to FIG. 7, the guide profile 412 can remain essentially unchanged
when retrofitting is carried out. Here, the web 427 of the guide profile
412 contains a series of bore holes 428 in a pattern of holes
corresponding to the photoelectric barrier arrangement. The photoelectric
strips 417 are attached to the outside of the web 427.
So that the beams of the photoelectric barrier arrangement which lead from
the transmitter to the receiver can run in the area of movement of the
leading edge 21 of the door, the safety device has a specific control
circuit with which the beams are sequentially assigned period activation
states as a function of the position and the movement of the door leaf.
This will be explained in more detail below:
In each case that beam 19-0 which is nearest to the leading edge 21 when
the door closes receives transition state ZERO from the control circuit
40, i.e. if the edge 21 passes through this light beam shortly afterwards
this photoelectric barrier does not emit a signal which interrupts the
closing movement of the door leaf.
All the beams 19-x which lie behind the beam 19-0 in the direction of
movement and have already been covered by the door leaf assume the
inactive state X.
On the other hand, the beams 19-1 to 19-n are in the active state 1, i.e.
each obstacle in the region of the beams 19-1 to 19-n ultimately supplies
an output signal SA which is applied to an interrupter or inverter relay
41 in order to interrupt or reverse the drive of the motor. It is clear
from the illustration according to FIG. 1 that the controller 42 of the
door drive is thus detached from the safety device 40, i.e. that both
devices 40, 42 operate independently of one another.
When the door leaf reaches the beam 19-0, the control circuit ensures that
the beam 19-0 becomes the passive beam 19-x, while the beam 19-1 becomes
the new beam 19-0. Thus, when the door leaf closes, all the beams change
sequentially from the active state 1 into the transition state ZERO and
finally into the passive state x, specifically controlled automatically by
the movement of the door leaf. An exception to this is formed by the top
beam which begins with the transition state ZERO.
The safety device serves simultaneously as a device for determining the
position of the door leaf. For this purpose, preferably when the door is
opened, the released beams are sequentially changed into the active state
1 via the transition state ZERO.
FIGS. 8 and 9 show a possible embodiment for the actuation of the
photoelectric area sensor and the evaluation of the signals present at the
individual photoelectric barriers. FIG. 8 shows the transmitter component
40-2, and FIG. 9 shows the associated receiver component 40-1.
The individual sensors S1 to Sn, for example in the form of light emitting
diodes, and the receivers E1 to En in the form of phototransistors, i.e.
the photoelectric barriers, can be addressed and evaluated individually by
means of a multiplexer arrangement MUX1 to MUX4 which is known per se.
That is to say the individual transmitters, such as for example light
emitting diodes, can be switched on and off selectively and individually
under the control of the microcontroller.
On the other hand, at the receiver end the signals which are received by
the receiver, such as for example by the phototransistors, can be
evaluated individually and selectively by means of the receiver-end
microcontroller. For this purpose, filter circuits (43), amplifier
circuits (44) and threshold value circuits 45 (Schmitt trigger) can be
used to eliminate interference influences.
This arrangement can also be used to gate out selectively determined
photoelectric barriers on an individual basis in order to represent, for
example, a brief entrance via a threshold ramp or else the presence of a
momentarily high coverage of snow.
Finally, the program sequence on which the safety device is based will be
explained with reference to FIG. 10:
The system is initialized in step 1. The position of the leading edge of
the door is determined, it being already possible at this point to access
again the signals present at the individual addresses. The current
position of the edge of the door will be assumed to be the x-th address,
i.e. the x-th beam.
If an object is detected during the determination of the position, the
control circuit emits an output signal SA, i.e. the outputs are set.
Otherwise, the photoelectric area sensor is evaluated starting from the
position x+2, i.e. the address x+1 is given the state ZERO and all the
beams x+2 to x+n are active.
If an obstacle is then sensed, the outputs are set. Otherwise, the routine
starts again.
If the door is opened, the passive beams X are successively switched to
"1", i.e. activated. Then, the same program steps as for closing occur,
but inverted. If the door is then stopped, the last beam to be released is
set to the "ZERO" activation state, i.e. it becomes the Run beam.
Of course, deviations from the previously described embodiments are
possible without departing from the basic idea of the invention:
Thus, the beam protection is not necessarily restricted to light beams.
It is also possible for transmitters and receivers to be assigned to a
single guide rail, so that a reflective photoelectric barrier is used. It
is also possible to operate with a series of reflective light sensors.
In the illustrated exemplary embodiments, the light source may be, for
example, a conventional light bulb, a light emitting diode or a laser. The
light receiver unit can be a photoelectric receiver such as, for example,
a photoelectric cell, a photoresistor, a photoelement or a photodiode.
Thus the invention provides a safety device for preferably vertically
moving, motor-operated doors such as, for example, segmented doors or
rolling shutter doors whose door leaf is capable of being moved in a
guided fashion. The movement path of a leading door edge is monitored by a
preferably optical beam protection, preferably on the basis of infrared
beams. The beam protection has at least two, preferably at least three or
a plurality of preferably parallel beams which are arranged staggered in
the direction of movement of the door and which are emitted on one side of
the door and are received or reflected on the other side of the door.
Furthermore, a safety circuit is proved with which the closing movement of
the door is stopped if an obstacle is sensed in the movement path of the
door. The beam protection is arranged in such a way that the beam area
which is defined by the beams has at least one line in common with the
movement area through which the leading door edge passes, and that the
safety device which operates autonomously has a beam-state control device
which assigns various activation states to the beams as a function of the
position and the movement of the door.
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